Tourism New Zealand (TNZ) chief executive Kevin Bowler said the movie franchise, including the Lord of the Rings trilogy, could overtake the leading franchise movies, the James Bond and Star Wars series, in box office sales.

The Battle of the Five Armies is due to be released late this year.

"There are only two film franchises that are currently bigger, James Bond and Star Wars, and with one film still to go, potentially it could be the biggest film franchise in the history of the world," Bowler said.

TNZ was tying its 100 per cent New Zealand brand to a 100 per cent Middle-earth brand to boost awareness of the Kiwi locations.

A good part of the growth in visitor numbers from countries like the United States, Germany and Japan could be attributed to the success of the first two The Hobbit movies, he said.

Research by the New Zealand Institute of Economic Research (NZIER) backed the worth of The Hobbit movies.

"If we go back to two years ago, the growth was all about China. The only real market was China," Bowler said.

"The US was flat, the UK was going backwards, Germany was pretty flat.

"Now, in today's terms, we've got growth from all those markets, and we've got the continuation of the Asian story."

Traveller numbers to New Zealand from the United States last year rose 13.4 per cent from 2012, Britain grew 2 per cent, Japan rose up 3.4 per cent and Germany rose 9 per cent.

"[NZIER] came back to us and said the thing that's making the difference is Middle-earth," he said.

"It's really cutting through. You've got this huge interest in these films and [without it] ... in some markets you would have gone backwards."

The third movie could prove to be the biggest and take the Sir Peter Jackson franchise to the top.

"So what that says to us in the year commencing July 2014, we should continue to back that horse because it's doing really well for us," Bowler said.

"We're looking to increase our spend in the market that's responding really well to it."